LJUNGMAN HERRING'S MODE OF LIFE. 511 



The mode of life of the herrings when gathered in schools finally de- 

 rerves some remarks. 



The herring is one of the most gregarious fish ; from its tenderest age 

 it gathers into schools, and only in very exceptional cases lives in soli- 

 tude. 



Between the spawning seasons the herrings certainly scatter a little 

 more, and generally go farther away from the coast to seek their food, 

 but it is an erroneous idea that during this period the schools are 

 entirely broken up. When the spawning season approaches, the smaller 

 schools gather into larger ones, which finally assume such enormous di- 

 mensions as to deserve the name of " herring mountains." When such 

 an enormous mass of herrings approaches the coast, it gives a peculiar 

 color to the water, and when near the surface creates a considerable 

 commotion in the water. 



When a large mass of herrings are gathered in one place, many air- 

 bubbles rise to the surface, which circumstance doubtless contributes 

 its share towards coloring the water. The Norrland fishermen say that 

 the herring " is milling," and from the size of the air bubbles draw 

 their conclusions as to the depth at which the herrings are. The 

 smaller the bubbles the deeper the herrings are supposed to be. Also 

 on the coast of Bohuslan these so-called "herring bubbles" form an im- 

 portant mark for 'the fishermen, who thereby judge not only of the ap- 

 proach of the herrings, but also of the depth at which they will be found. 

 If the bubbles burst when reaching the surface, the herrings are in deep 

 water ; if they float for some time on the surface, the herrings are nearer 

 the surface. These air bubbles can best be observed during day fishing 

 with large seines, and they will then by their greater or smaller number 

 indicate in how far the haul will be successful or not. 



French and English authors say that according to the observations of 

 many fishermen the location and size of a school of herrings are indicated 

 by an oily substance ("graiss m" u smcW) floating near the surface, which 

 is considered a favorable sign for the fisheries. The French Channel 

 fishermen say when they see this that the water is u pouilleuse." Some 

 authors explain this phenomenon as being caused by herrings which have 

 been torn to pieces by sharks (Squahts acanthias L.), and say that it is 

 a sure indication that sharks are near. Bartlett's explanation, however, 

 seems better, according to which this oily substance is formed from the 

 numerous excrements of the herrings. 14 Strange to say, this phenom- 

 enon has both in old and modern times been by some confounded with 

 the whitish substance floating about near the surface during the spawn- 

 ing season of the herring. 



It is also said that the large and dense schools of herrings when 

 spawning, or when swimming near the surface in large schools, pro- 

 duce a peculiar odor, which has often been observed by the Norrland 

 fishermen. 



"Report on the herring fisheries of Scotland. London, 1878, p. 169. 



